Seong-Cheol Kim's research while affiliated with Seoul National University and other places

Publications (266)

Article
span>In the modern world, the consumption of oil, coal natural gas, and nuclear energy has been causing by a serious environmental problem and an ongoing energy crisis. The generation and consumption of renewable energy sources (RESs) such as solar and wind tidal, can resolve the problem but the nature of the RESs is fluctuating and intermitted. Th...
Preprint
We develop joint vehicle tracking and road side unit (RSU) selection algorithms suitable for vehicle-to-infrastructure (V2I) communications. We first design an analytical framework for evaluating vehicle tracking systems based on the extended Kalman filter. A simple, yet effective, metric that quantifies the vehicle tracking performance is derived...
Chapter
This chapter presents the design and analysis of brushless DC (BLDC) motor driver for hybrid electric vehicles. Due to the combustion of petroleum, it is going to create a pollution problem. Therefore, it is needed that alternating energy resources for petroleum reserves which are exhaustible in potential are required to be determined. The majority...
Article
For the high-resolution DoA (Direction of Arrival) estimation, various multiplexing schemes are considered for the multi-input multi-output (MIMO) fast chirp frequency-modulated continuous-wave (FMCW) radar. However, current schemes such as time-division multiplexing (TDM) and binary-phase modulation (BPM) may reduce the maximum detectable velocity...
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p>This paper addresses the comprehensive analysis of various energy storage technologies, i.e., electrochemical and non-electrochemical storage systems by considering their storage methods, environmental impact, operations, costs, and their importance and applications. These storage technologies will help to reduce the energy shortage. There has be...
Article
Vehicle-to-everything communication system is a strong candidate for improving the driving experience and automotive safety by linking vehicles to wireless networks. To take advantage of the full benefits of vehicle connectivity, it is essential to ensure a stable network connection between roadside unit (RSU) and fast-moving vehicles. Based on the...
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Abstract The target classification of unknown classes using radar sensor data is discussed. The neural network‐based classifier shows high classification accuracy for the learned class targets. However, there is a risk of false decision for the untrained class target owing to an overconfidence problem. The output confidence of the classifier is cal...
Article
In automotive frequency-modulated continuous wave radar systems, targets with similar ranges and velocities might be detected as a single target because their target information overlaps on the range-velocity (RV) plane. When the information of multiple targets overlaps on the RV plane, target classification cannot be performed accurately. Therefor...
Article
Ranging methods using received signal strength (RSS) information are widely used for indoor localization because they can be easily implemented without conducting site surveys. However, range estimation with a single pathloss model produces considerable errors, which degrade the positioning performance. This problem mainly arises because the single...
Article
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In a multiple-input multiple-output (MIMO) radar system, binary phase-shift keying (BPSK) modulation is widely used to separate signals transmitted from multiple transmit (Tx) antennas. However, when the BPSK modulation is applied to the frequency-modulated continuous-wave (FMCW) radar system, there is an issue of Doppler-angle ambiguity due to the...
Article
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In this paper, we propose a hybrid localization algorithm to boost the accuracy of range-based localization by improving the ranging accuracy under indoor non-line-of-sight (NLOS) conditions. We replaced the ranging part of the rule-based localization method with a deep regression model that uses data-driven learning with dual-band received signal...
Preprint
A vehicle-to-everything communication system is a strong candidate for improving the driving experience and automotive safety by linking vehicles to wireless networks. To guarantee the full benefits of vehicle connectivity, it is essential to ensure a stable network connection between the roadside unit (RSU) and fast-moving vehicles. Based on an ex...
Article
Full-text available
In this paper an optimal energy and reactive power dispatch problem is solved by using the ant lion optimization (ALO) algorithm by considering the total cost minimization and social welfare maximization (SWM) objectives. Two different market models are proposed in this work, i.e., conventional/sequential market clearing and the proposed/simultaneo...
Article
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Abstract Modern autonomous vehicles are being equipped with various automotive sensors to perform special functions. Especially, it is important to predict the heading direction of the front vehicle to adjust the speed of the ego‐vehicle and select appropriate actions. Here, we propose a method for estimating the instantaneous heading direction of...
Article
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The received-signal-strength (RSS) is widely used in the range-based localization because of its practical advantages such as low-cost and low-complexity. For accurate ranging based on the RSS in indoor environments, well-defined propagation models that consider the distortion of the RSS due to abrupt obstructions are required. This paper proposes...
Article
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span>The objective of this paper is to study various methods adopted during the energy audit. Many countries are focusing on energy, not only enhancing the tenable power generation sources but also on utilizing the power more proficiently for economic utilization. The energy audit is an important parameter for all the developing and developed count...
Article
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When a packet is transmitted using orthogonal frequency-division multiplexing (OFDM) transmission in IEEE 802.11ad, channel frequency responses (CFR) cannot be fully estimated using the common preamble of a packet, because the bandwidth of the estimated CFR using the common preamble is narrower than that of the data-field of OFDM transmissions. Thi...
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This paper proposes quick & accurate islanding detection technique for a distribution system with distributed generators (DGs). Here two schemes of islanding detection based on signal processing is proposed of which one is based on discrete wavelet transform (DWT) with artificial neural network (ANN), and another one is based on S-transform with AN...
Article
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This paper proposes a new technique for a voltage source multilevel inverter (MLI) with reduced switch count, and it creates a smoother sinusoidal output waveform with reduced total harmonic distortion (THD). Therefore, the proposed technique identifies a better position in the list of multilevel converters used for power quality conditioners. Semi...
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p>This paper presents the importance and applications of smart cities in view of taxonomy in urbanization particularly in Asia and Africa economies. It describes the characteristics and architecture of smart cites and reviews on the recent technological developments. The paper analyses the social impacts due to up-gradation of existing cities. The...
Article
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This study proposes an advanced direction‐of‐arrival (DOA) estimation method for automotive multiple‐input multiple‐output (MIMO) fast‐ramp radar systems. To distinguish the transmitted signal at the receiving antenna, the orthogonal code can be applied to each transmitted signal. In this case, to correctly estimate the angles of the targets, the a...
Article
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In this paper, we present an in-vehicle people localization technique using a deep neural network (DNN) model that is trained by the experimental data. First, an impulse radio ultra-wide band (IR-UWB) radar is installed inside the vehicle, and received signals are acquired by changing the arrangement of people sitting. Then, on the acquired data, w...
Article
Generally, automotive radars are installed behind bumpers, perpendicular to the ground. After mounting the radar, the mounting angle is often distorted due to external shock during driving. If the radar is tilted toward the ground or sky, its detection performance can be severely degraded, and this can pose a serious threat to the safety of drivers...
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In this paper, we propose a new technique for exact recovery of missing data due to impulsive noise in time-domain sampled acoustic waves, named as sketching and stacking with random fork (SSRF). Existing methods recover the original signal from the corrupted sequence based on the correlation between each element of the signal or between the bases...
Article
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In this study, we propose a method to recognize road environments with automotive frequency-modulated continuous wave (FMCW) radar systems. For automotive radar systems on the road, diverse road environments are observed. Each road environment generates unnecessary echoes known as clutter, and the magnitude distribution of received radar signal var...
Article
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When a radar signal generated by another vehicle arrives at an ego-vehicle, mutual interference occurs, which can seriously degrade the detection performance of the radar. To mitigate mutual interference, the type of radar modulation used in the interference vehicle must be identified because the types of radar systems installed in each vehicle are...
Article
This paper presents an efficient mutual interference suppression method using wavelet denoising in automotive radar systems. When a radar signal transmitted from another radar-equipped vehicle flows into our radar system, it acts as an interference signal and degrades the target detection performance. With wavelet denoising, the interference signal...
Article
Nowadays, various sensors are being widely used in indoor environments to improve quality of life. In particular, sensors can be installed inside a car to detect dangerous situations, such as a child or a pet being left alone in a car. In this paper, we present an effective method for monitoring people inside a vehicle by using impulse radio ultra-...
Article
This study proposes a new method to estimate room shape using radio waves. Unlike existing heuristic methods, the proposed method uses accumulated radio channel data and the neural network to predict room shapes. The radio channel data is generated by three dimensional (3D) ray tracing simulation and actual measurements. The neural network used the...
Article
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This study proposes an artificial neural network‐based method to classify road structures for automotive radar systems. Generally, road structures generate unwanted echoes called clutter, which degrades the performance of target detection, and may cause critical errors in autonomous driving modes. However, recognition and classification of each ind...
Article
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As the importance of radar sensors for automotive vehicles has rapidly increased, the mutual interference between vehicle radars has become important. If two or more radars share the same transmitting frequency band, their interference effects are retained after low‐pass filtering. These interference signals can degrade the performance of target es...
Article
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In automotive radar systems, a limited number of antenna elements are used to estimate the angle of the target. Therefore, array interpolation techniques can be used for direction of arrival (DOA) estimation to achieve high angular resolution. In general, to generate interpolated array elements from original array elements, the method of linear lea...
Article
This paper proposes a novel congestion management (CM) approach within an optimal power flow (OPF) framework in the context of restructured power markets. The conventional OPF problem is modified to include a mechanism which enables the market players to compete and trade, and simultaneously ensuring the secured system operation. In this paper, bot...
Article
An enhanced high-density clutter recognition and suppression method for automotive frequency-modulated continuous wave (FMCW) radar systems is presented in this paper. In a high-density clutter environment such as guardrails, tunnels, and soundproof walls, the target detection performance is degraded because many undesired beat frequency components...
Article
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p>Congestion management (CM) in the deregulated power systems is germane and of central importance to the power industry. In this paper, an optimal power flow (OPF) based CM approach is proposed whose objective is to minimize the absolute MW of rescheduling. The proposed optimization problem is solved with the objectives of total generation cost mi...
Article
In this paper, we propose an enhanced direction-of-arrival (DOA) estimation method using linearly predicted array expansion to improve the angular resolution for automotive radar systems with a small number of antenna elements. The proposed method extracts the linear relation among signals received in the array antenna and uses it to generate extra...
Article
A method for improving the ranging performance for the localization using orthogonal frequency-division multiplexing-based communication system is proposed. The most difficult aspect of performing localization using the time-of-arrival information of a communication system is distinguishing indirect paths and noise from the direct path (DP) when th...
Article
This paper presents an interference suppression and signal restoration technique that can create the clean signals required by automotive frequency-modulated continuous wave radar systems. When a radar signal from another radar system interferes with own transmitted radar signal, the target detection performance is degraded. This is because the bea...
Article
In recent years, ray tracing simulation is widely adopted to model outdoor radio propagation. However, existing studies have not focused on the blockage effect of roadside trees. In this study, we model roadside trees using a variety of techniques to analyze their effect on the accuracy of channel modeling using ray tracing simulation. The roadside...
Article
In this article, the reduced size of the ultra‐wide band (UWB) band‐pass filter (BPF) with λg/4 short stubs using π‐type meander structure and folding short stubs is presented. The π‐type meander structure and folding short stubs are adopted instead of the λg/4 transmission line (TL) and λg/4 short stubs to reduce the size of the proposed BPF. The...
Article
This paper proposes an efficient road structure recognition method using statistical characteristics of received signals in automotive frequency-modulated continuous wave radar systems. Generally, roads consist of various structures, some of which, such as tunnels and soundproof walls made of iron, generate undesired echoes, called clutter. When th...
Article
Self-organizing localization is a crucial feature of wireless sensor networks (WSNs) that cannot employ positioning techniques such as the global positioning system (GPS). If the number of anchor nodes is insufficient, it is difficult to estimate each node’s location using the anchor nodes’ information by employing the existing algorithms, the loca...
Article
This study demonstrates a signal-to-noise ratio (SNR) analysis and estimation algorithm for efficient phase noise mitigation that can be practically applied to single-carrier frequency-domain-equalisation (SC-FDE) systems that operate in millimetre-wave bands. First, the effect of phase noise in SC-FDE systems is investigated on each of the packet...
Article
In this study, the authors propose a periodic clutter suppression method in iron road structures for automotive radar systems. Specific road structures made of iron such as tunnels, soundproof walls, and guardrails have periodic steel frames that generate unwanted reflected signals called radar clutter. This clutter degrades the detection performan...
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Localization is an essential service for numerous applications in wireless ad hoc networks. In particular, cooperative localization is a widely used technique for improving performance by utilizing information obtained from adjacent sensors. In general, distributed localization in ad hoc networks shows relatively low performance compared to central...
Article
In this study, the channel characteristics and cell coverage of the 28 GHz millimeter-wave (mmWave) band outdoors are investigated by developing an efficient threedimensional ray-tracing simulation. First, the accuracy of the simulation is verified by comparing its results with actual measurements. The path loss (PL) agrees well in both lineof- sig...
Article
The millimeter-wave (mmWave) band has attracted great attention as a promising spectrum for the next generation cellular systems. However, mmWave communication systems have encountered several challenges because of different electromagnetic characteristics compared with existing spectrum below-6 GHz systems. In order to evaluate the technical feasi...
Article
Inter-cell interference coordination (ICIC) is a promising technique to improve the performance of frequency-domain packet scheduling (FDPS) in downlink LTE/LTE-A networks. However, it is difficult to maximize the performance of FDPS using static ICIC schemes because of insufficient consideration of signal-to-interference-and-noise ratio distributi...
Article
This paper proposes a distributed localization algorithm in wireless sensor networks. The algorithm considers the position uncertainty of reference nodes which have been ignored in the past research in which an imperfect position information of reference nodes intensifies the error accumulation phenomenon. The algorithm calculates position uncertai...